High-performance water-based drilling fluid for maintaining stable shale strength and preparation method thereof

Abstract

The invention relates to the field of drilling fluids for petroleum and natural gas drilling, in particular to a high-performance water-based drilling fluid capable of keeping the strength of shale stable and a preparation method of the high-performance water-based drilling fluid. The high-performance water-based drilling fluid capable of keeping stable shale strength is prepared from the following raw materials in parts by weight: 8-12 parts of bentonite for drilling, 0.8-1.0 part of sodium hydroxide, 20-28 parts of a composite blocking agent, 14-20 parts of a filtrate reducer, 12-15 parts ofa polymeric alcohol anti-collapse agent, 8-12 parts of a long-chain alcohol amine ester extreme pressure antifriction agent, 12-20 parts of potassium chloride, 2-4 parts of a polyamine inhibitor, 260-400 parts of a weighting agent and 400 parts of water. According to the invention, the water-based drilling fluid with high plugging, high lubrication, high inhibition, low water loss and high-temperature stability is obtained through the interaction of the components and the respective preparation method of a glue solution and a soil phase.

Description

technical field [0001] The invention relates to the field of drilling fluid used for oil and natural gas drilling, and more specifically relates to a high-performance water-based drilling fluid for maintaining stable shale strength and a preparation method thereof. Background technique [0002] In the development of Fuling shale, long horizontal sections are usually used to drill shale formations. In order to solve the problems of wellbore stability and high friction in long horizontal well sections, oil with strong inhibition and good lubricity is preferred in the drilling process at home and abroad. However, with the continuous deepening of domestic shale gas development in recent years, in addition to solving many technical problems in long horizontal well sections (such as: well trajectory, wellbore stability, resistance reduction and anti-sticking, etc.), the underground The protection of the environment and the surrounding ecological environment is urgent, and the pres...

AI Technical Summary

Problems solved by technology

[0002] In the development of Fuling shale, long horizontal sections are usually used to drill shale formations. In order to solve the problems of wellbore stability and high friction in long horizontal well sections, oil with strong inhibition and good lubricity is preferred in the drilling process at home and abroad. However, with the continuous deepening of domestic shale gas development in recent years, in addition to solving many technical problems in long horizontal well sections (such as: well trajectory, wellbore stability, resistance reduction and anti-sticking, etc.), the underground The protection of the environment and the surrounding ecological environment is urgent, and the pressure on environmental protection is increasing. Major technical service companies at home and abroad have been trying to develop water-based drilling fluids with properties similar to those of oil-based drilling fluids, so as to realize "water for oil". For example, Baker Hughes' PERFORMAX, Schlumberger M-1's ULTRADRIL and Halliburton have all successfully applied water-based systems in some wells. There are also domestic cases of successful research and development of high-performance water-based drilling fluids. However, the high-performance water-based drilling fluids in the prior art still have certain deficiencies in performance such as temperature resistance.

[0003] The Chinese patent with publication number CN 107652952A proposes a high-performance water-based drilling fluid suitable for long horizontal sections of shale gas, which includes water, bentonite, caustic soda, multifunctional compounding agent, medium molecular weight fluid loss reducer, and high-efficiency coating agent , anti-slump lubricant, plugging fluid loss reducer, inhibitor, nano plugging agent and speed-up lubricant, the drilling fluid is prepared with water-based, used to replace oil-based drilling fluid, to solve the problem of oil-based drilling cuttings disposal and other environmental protection However, the temperature resistance of this water-based drilling fluid is only 120°C, so the field application is limited, and the asphalt-based anti-slump lubricant is used for post-drilling treatment, and the treatment cost is too high

Therefore, the existing technology has a large room for improvement

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